There have been recent significant improvements in the short-term survival of solid organ transplantation patients due to advances in immunosuppression and transplant techniques. However, long-term graft survival has still lagged behind other outcomes and has now become one of the main problems in solid organ transplantation. For this Special Issue, we invited researchers and clinicians to submit studies on solid organ transplantation. These have provided us with additional knowledge and skills that will ultimately help us to improve outcomes after solid organ transplantation.